Scheduler, substrate processing apparatus, and substrate conveyance method

ABSTRACT

A calculation amount and calculation time for a substrate conveyance schedule are reduced. A scheduler is provided which is incorporated in a control section of a substrate processing apparatus including a plurality of substrate processing sections that process a substrate, a conveyance section that conveys the substrate, and the control section that controls the conveyance section and the substrate processing sections, and calculates a substrate conveyance schedule. The scheduler includes: a modeling section that models processing conditions, processing time and constraints of the substrate processing apparatus into nodes and edges using a graph network theory, prepares a graph network, and calculates a longest route length to each node; and a calculation section that calculates the substrate conveyance schedule based on the longest route length.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims benefit of priority from Japanese Patent Application No. 2018-036660 filed on Mar. 1, 2018, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a scheduler, a substrate processing apparatus, and a substrate conveyance method.

BACKGROUND ART

There are substrate processing apparatuses of various configurations. For example, generally, the substrate processing apparatus including a substrate storage container that houses a plurality of substrates, a plurality of conveyers and a plurality of processing sections is known. In the substrate processing apparatus, the plurality of substrates are successively fed from the substrate storage container into the apparatus, conveyed between the plurality of processing sections by the plurality of conveyers and processed in parallel, and the processed substrates are collected in the substrate storage container. In addition, the substrate processing apparatus including the plurality of substrate storage containers that are made replaceable is also known. In such a substrate processing apparatus, by appropriately replacing the substrate storage container loaded with the processed substrates with the substrate storage container loaded with unprocessed substrates, an operation of the substrate processing apparatus can be continuously performed.

As one example of the substrate processing apparatus described above, a plating apparatus that performs bump formation, TSV formation and rewiring plating is known, for example. In such a substrate processing apparatus, it is demanded to realize high throughput while satisfying a strict process constraint (a predetermined process time interval from start of a certain process to start of the next process). In order to satisfy the strict demand, various scheduling methods for making an optimum substrate conveyance plan have been considered for substrate conveyance control of the plating apparatus. The substrate processing apparatus that calculates a substrate conveyance schedule using a simulation method as the scheduling method is known (PTL 1).

CITATION LIST Patent Literature

PTL 1 Japanese Patent No. 5620680

SUMMARY OF INVENTION Technical Problem

In a case of calculating a substrate conveyance schedule using a simulation method, in order to obtain excellent throughput, simulation calculation is performed respectively for combinations of many parameters related to scheduling based on processing conditions and constraints given in advance so that there is a problem that a calculation amount becomes huge and it is not suitable for an actual operation as the substrate processing apparatus. As the solution, it is conceivable to search parameter setting by which a throughput value becomes maximum for a process recipe condition assumed at the point of time of design and narrow down a parameter range assumed to be optimum. When executing actual substrate processing, substrate conveyance simulation is performed for the respective parameters, evaluation values of the throughput are measured, and the parameter to be a maximum throughput value is selected from them. In such a manner, by narrowing down the parameter range assumed to be optimum from a group of many existing parameters, it is needed to shorten simulation calculation time in the actual operation and prevent substrate processing start from being obstructed.

However, in order to prepare the range that the simulation calculation time when loaded on the apparatus is within the calculation time not obstructing the actual operation, which is the parameter range assumed to be optimum, calculation processing in advance of a long period of time (five hours, for example) is needed. In addition, since the prepared parameter range assumed to be optimum is determined based on the assumed process recipe condition, there is a problem that the excellent throughput cannot be achieved in the case that the condition other than the assumed process recipe condition is given or in the case that the substrate processing apparatus is in a nonstationary state of a fault or the like.

The present invention is implemented in consideration of the above-described point. The object is to reduce a calculation amount and calculation time for a substrate conveyance schedule and obtain excellent throughput under any conditions.

Solution to Problem

According to a first aspect of the present invention, a scheduler is provided which is incorporated in a control section of a substrate processing apparatus including a plurality of substrate processing sections that process a substrate, a conveyance section that conveys the substrate, and the control section that controls the conveyance section and the substrate processing sections, and calculates a substrate conveyance schedule. The scheduler includes: a modeling section that models processing conditions, processing time and constraints of the substrate processing apparatus into nodes and edges using a graph network theory, prepares a graph network, and calculates a longest route length to each node; and a calculation section that calculates the substrate conveyance schedule based on the longest route length. The modeling section defines as one unit a predetermined number of the substrates out of the substrates for which graph networks are to be prepared and prepares a graph network for each of the substrates. The scheduler fixes one of the prepared graph networks. The modeling section defines as another one unit a predetermined number of the substrates out of the substrates for which graph networks are to be prepared except for the substrates for which the graph networks have already been fixed, and prepares a graph network for each of the substrates in the other one unit to add to the fixed graph network. The scheduler fixes one of the added graph networks.

According to the one aspect, the substrate conveyance schedule is calculated based on the longest route length to each node modeled using the graph network theory. Therefore, the substrate conveyance schedule can be calculated without performing advance calculation processing for narrowing down a parameter range that conventionally needed a lot of calculation time so that a calculation amount and calculation time can be reduced. In addition, since it is not needed to limit parameters (processing conditions) for obtaining optimum throughput beforehand, the substrate conveyance schedule capable of achieving the excellent throughput even in the case that the condition other than the assumed process recipe is given can be calculated. Further, according to the one aspect, while a predetermined number of the substrates is defined as one unit (mini batch) and graph networks for the substrates are prepared and optimized, the graph network is fixed for each substrate. Therefore, compared to the case of preparing and then optimizing graph networks for the entire specified processing number, it is possible to more easily obtain an efficient conveyance order and to reduce the calculation time. In addition, since a graph network can be additionally prepared for each substrate, even when a new substrate is fed during execution of the substrate conveyance, it is possible to deal with such supply. By arbitrarily changing the number of the substrates in the mini batch according to the processing conditions, the condition of short calculation time can be selected.

According to a second aspect of the present invention, in the scheduler of the first aspect, a start time of the processing on the substrate for which the graph network has been prepared is calculated, and the start time of the processing is fixed.

According to the one aspect, the calculation processing of the longest route length can be reduced.

According to a third aspect of the present invention, in the scheduler of the second aspect, the start time of the processing on the substrates for which the graph network has been fixed is fixed when the start time of the processing remains unchanged at the time of adding the graph network for the substrate in the other one unit to the fixed graph network.

According to the one aspect, when the start time of each processing on the substrate remains unchanged over a predetermined period, the start time of each processing is fixed. Therefore, compared to the case of leaving the processing start time of each operation for the entire specified processing number in a variable state, the calculation processing of the longest route length can be reduced. In addition, by arbitrarily changing a start time fixing determination number according to the processing conditions, the condition of short calculation time can be selected.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the modeling section prepares graph networks for all the substrates for which graph networks are to be prepared.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the scheduler includes a detection section that detects whether or not the substrate processing apparatus has shifted to a nonstationary state, the modeling section models the processing conditions, the processing time, and the constraints of the substrate processing apparatus in the nonstationary state to the nodes and the edges by using the graph network theory when the detection section detects that the substrate processing apparatus has shifted to the nonstationary state, prepares the graph network, and calculates the longest route length to each node, and the calculation section is configured to calculate the substrate conveyance schedule based on the longest route length to each node in the nonstationary state.

According to the one aspect, even when the substrate processing apparatus shifts to the nonstationary state, since the substrate conveyance schedule is calculated based on the longest route length to each node in the nonstationary state, the substrate conveyance schedule appropriate in the nonstationary state can be calculated.

According to a sixth aspect of the present invention, in the fifth aspect, the nonstationary state includes a state at the time of a fault of the substrate processing apparatus, a state at the time of maintenance of the substrate holder, or a state at the time of maintenance of an anode holder.

According to the one aspect, the appropriate substrate conveyance schedule in a sudden nonstationary state such as the fault of the substrate processing apparatus can be calculated. In addition, the substrate holder and the anode holder sometimes need cleaning and inspections when used for a long period of time, and are maintained (cleaned or inspected) periodically by being taken out from the substrate processing apparatus or inside the substrate processing apparatus. According to the one aspect, even in the nonstationary state that is periodically generated such as the maintenance, the appropriate substrate conveyance schedule can be calculated.

According to a seventh aspect of the present invention, a substrate processing apparatus including the control section incorporating the scheduler of any one of the first to sixth aspects is provided. In the substrate processing apparatus, the control section is configured to control the conveyance section based on the calculated substrate conveyance schedule.

According to the one aspect, the substrate can be appropriately conveyed based on the calculated substrate conveyance schedule.

According to an eighth aspect of the present invention, a substrate conveyance method using a substrate processing apparatus including a plurality of substrate processing sections that process a substrate, a conveyance section that conveys the substrate, and a control section that controls the conveyance section and the substrate processing sections is provided. The substrate conveyance method includes: a modeling step of modeling processing conditions, processing time and constraints of the substrate processing apparatus into nodes and edges using a graph network theory, preparing a graph network, and calculating a longest route length to each node; a calculation step of calculating a substrate conveyance schedule based on the longest route length; and a step of conveying the substrate based on the substrate conveyance schedule. The calculation step includes a step of defining as one unit a predetermined number of the substrates out of the substrates for which graph networks are to be prepared and preparing a graph network for each of the substrates, a step of fixing one of the prepared graph networks, a step of defining as the other one unit a predetermined number of the substrates out of the substrates for which graph networks are to be prepared except for the substrates for which the graph networks have already been fixed, and preparing a graph network for each of the substrates in the other one unit to add to the fixed graph network, and a step of fixing one of the added graph networks.

According to the one aspect, the substrate conveyance schedule is calculated based on the longest route length to each node modeled using the graph network theory. Therefore, the substrate conveyance schedule can be calculated without performing advance calculation processing for narrowing down a parameter range that conventionally needed a lot of calculation time so that the calculation amount and the calculation time can be reduced. In addition, since it is not needed to limit parameters (processing conditions) for obtaining optimum throughput beforehand, the substrate conveyance schedule capable of achieving the excellent throughput even in the case that the condition other than the assumed process recipe is given can be calculated. Further, according to the one aspect, while a predetermined number of the substrates is defined as one unit (mini batch) and graph networks for the substrates are prepared and optimized, the graph network is fixed for each substrate. Therefore, compared to the case of preparing and then optimizing graph networks for the entire specified processing number, it is possible to more easily obtain an efficient conveyance order and to reduce the calculation time. In addition, since a graph network can be additionally prepared for each substrate, even when a new substrate is fed during execution of the substrate conveyance, it is possible to deal with such supply. By arbitrarily changing the number of the substrates in the mini batch according to the processing conditions, the condition of short calculation time can be selected.

According to a ninth aspect of the present invention, in the substrate conveyance method of the eighth aspect, the calculation step includes a step of calculating a start time of the processing on the substrate for which the graph network has been prepared, and a step of fixing the start time of the processing.

According to the one aspect, the calculation processing of the longest route length can be reduced.

According to a tenth aspect of the present invention, in the substrate conveyance method of the ninth aspect, the step of fixing the start time of the processing fixes the start time of the processing on the substrates for which the graph network has been fixed when the start time of the processing remains unchanged at the time of adding the graph network for the substrate in the other one unit to the fixed graph network.

According to the one aspect, when the start time of each processing on the substrate remains unchanged over a predetermined period, the start time of each processing is fixed. Therefore, compared to the case of leaving the processing start time of each operation for the entire specified processing number in a variable state, the calculation processing of the longest route length can be reduced. In addition, by arbitrarily changing the start time fixing determination number according to the processing conditions, the condition of short calculation time can be selected.

According to an eleventh aspect of the present invention, in the substrate conveyance method of any one of the eighth to tenth aspects, a step of detecting whether or not the substrate processing apparatus has shifted to a nonstationary state is provided, the modeling step includes a step of modeling the processing conditions, the processing time and the constraints of the substrate processing apparatus in the nonstationary state to the nodes and the edges using the graph network theory when it is detected that the substrate processing apparatus has shifted to the nonstationary state, preparing the graph network, and calculating the longest route length to each node, and the calculation step includes a step of calculating the substrate conveyance schedule based on the longest route length to each node in the nonstationary state.

According to the one aspect, even when the substrate processing apparatus has shifted to the nonstationary state, since the substrate conveyance schedule is calculated based on the processing conditions, the processing time and the constraints, the substrate conveyance schedule appropriate in the nonstationary state can be calculated.

According to a twelfth aspect of the present invention, in the eleventh aspect, the nonstationary state includes a state at the time of a fault of the substrate processing apparatus, a state at the time of maintenance of a substrate holder, or a state at the time of maintenance of an anode holder.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating a configuration example of a plating apparatus relating to an embodiment of the present invention;

FIG. 2 is a block diagram illustrating one example of a configuration of a control section;

FIG. 3 is a block diagram of a substrate conveyance control scheduler illustrated in FIG. 2;

FIG. 4 is a diagram illustrating one example of a graph network modeled by a modeling section illustrated in FIG. 3;

FIG. 5 is a graph network diagram illustrated in FIG. 4, to which a longest route length to each node is added;

FIG. 6 is a diagram for which an edge for avoiding contention of a conveyer is added to the graph network diagram illustrated in FIG. 5;

FIG. 7 is a graph network diagram illustrated in FIG. 6, to which the longest route length to each node is added;

FIG. 8 is a diagram illustrating a part of a substrate conveyance schedule;

FIG. 9 is a diagram illustrating one example of conveyance processing time of a loading robot set to the substrate conveyance control scheduler;

FIG. 10 is a diagram illustrating one example of conveyance processing time of a conveyer set to the substrate conveyance control scheduler;

FIG. 11 is a diagram illustrating one example of the conveyance processing time of the conveyer set to the substrate conveyance control scheduler;

FIG. 12 is a diagram illustrating one example of constraints set to the substrate conveyance control scheduler;

FIG. 13 is a diagram illustrating one example of an entire recipe set to the substrate conveyance control scheduler;

FIG. 14 is a diagram illustrating one example of a process recipe set to the substrate conveyance control scheduler;

FIG. 15 is a flowchart illustrating a substrate processing method relating to the present embodiment;

FIG. 16 is a flowchart illustrating subroutines of step S105;

FIG. 17 is a flowchart illustrating subroutines of step S203;

FIG. 18 is a flowchart illustrating subroutines of step S204;

FIG. 19 is a flowchart illustrating subroutines of step S105; and

FIG. 20 is a flowchart illustrating subroutines of step S510 illustrated in FIG. 19.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings described below, same signs are attached to same or corresponding components and redundant description is omitted. In the present embodiment, a substrate processing apparatus is described with a plating apparatus that performs plating on a semiconductor substrate as an example, but the substrate processing apparatus relating to the present invention is not limited to the plating apparatus, and the present invention is applicable to various kinds of substrate processing apparatuses such as the substrate processing apparatus that performs processing for manufacturing an LCD to a glass substrate.

FIG. 1 is a schematic diagram illustrating a configuration example of a plating apparatus relating to the embodiment of the present invention. The present plating apparatus 10 includes a loading port 11, a loading robot 12, an aligner 13, a spin rinse dryer (SRD) 14, fixing stations 15 a and 15 b, a substrate holder storage area 25 including a plurality of stockers 16, a pre-washing bath 17, a pretreatment bath 18, a washing bath 19, a rough drying bath (blow bath) 20, a washing bath 21, a plating area 26 (corresponding to one example of a plating section) including a plurality of plating baths 22, and two conveyers 23 and 24. The spin rinse dryer 14, the pre-washing bath 17, the pretreatment bath 18, the washing bath 19, the blow bath 20, the washing bath 21, and the plating baths 22 function as a substrate processing section that performs predetermined processing to a substrate. In addition, the loading robot 12 and the conveyers 23 and 24 function as a conveyance section that conveys the substrate.

In FIG. 1, arrows A indicate a loading transfer stroke of the substrate, and arrows B indicate an unloading transfer stroke of the substrate. On the loading port 11, a substrate storage container (FOUP: Front Opening Unified Pot) storing a plurality of unprocessed substrates and a plurality of processed substrates is mounted.

In the plating apparatus 10, the loading robot 12 takes out the unprocessed substrate from the substrate storage container mounted on the loading port 11, and mounts it on the aligner 13. The aligner 13 positions the substrate with a notch or an orientation flat or the like as a reference. Then, the loading robot 12 conveys the substrate to the fixing stations 15 a and 15 b, and the fixing stations 15 a and 15 b mounts the substrate on a substrate holder taken out from the stocker 16. The plating apparatus 10 is configured to mount the substrate on the respective substrate holders in the two fixing stations 15 a and 15 b and convey the two substrate holders as one set. The substrates mounted on the substrate holders are conveyed to the pre-washing bath 17 by the conveyer 23, pre-washed in the pre-washing bath 17, and then conveyed to the pretreatment bath 18. The substrate preprocessed in the pretreatment bath 18 is conveyed further to the washing bath 19, and washed in the washing bath 19.

The substrate washed in the washing bath 19 is conveyed to one of the plating baths 22 in the plating area 26 by the conveyer 24, and immersed in plating liquid. Plating is executed here and a metal film is formed on the substrate. The substrate on which the metal film is formed is conveyed to the washing bath 21 by the conveyer 24, and washed in the washing bath 21. Subsequently, the substrate is conveyed to the blow bath 20 by the conveyer 24, subjected to rough drying processing, then conveyed to the fixing stations 15 a and 15 b by the conveyer 23, and detached from the substrate holder. The substrate detached from the substrate holder is conveyed to the spin rinse dryer 14 by the loading robot 12, subjected to washing/drying processing, and then stored at a predetermined position of the substrate storage container mounted on the loading port 11.

The plating apparatus 10 relating to the present embodiment is divided, for convenience, into an apparatus preceding stage section including the loading robot 12 (corresponding to one example of a preceding stage conveyance section) that conveys the substrate between the loading port 11 and the fixing stations 15 a and 15 b, and an apparatus subsequent stage section including the conveyers 23 and 24 (corresponding to one example of a subsequent stage conveyance section) that conveys the substrate between the fixing stations 15 a and 15 b and the plating area 26. In the plating apparatus 10 relating to the present embodiment, as described later, a preceding stage side graph network in the apparatus preceding stage section and a subsequent stage side graph network in the apparatus subsequent stage section are separately calculated.

Subsequently, a control section that controls the plating apparatus 10 illustrated in FIG. 1 will be described. FIG. 2 is a block diagram illustrating one example of a configuration of the control section. Conveyance control of the loading transfer stroke of the substrate indicated by the arrows A by the loading robot 12, the conveyer 23 and the conveyer 24 and conveyance control of the unloading transfer stroke of the substrate indicated by the arrows B, which are illustrated in FIG. 1, are performed by control of the control section.

The control section of the plating apparatus 10 includes an apparatus computer 30 and an apparatus controller 32. The apparatus computer 30 mainly performs calculation and data processing or the like, and the apparatus controller 32 is configured to mainly control the respective sections of the plating apparatus 10 illustrated in FIG. 1. In the present embodiment, the apparatus computer 30 and the apparatus controller 32 are separately configured, but without being limited thereto, the apparatus computer 30 and the apparatus controller 32 may be configured as an integrated control section.

The apparatus computer 30 includes an operation screen application 31 that makes an operation screen be displayed at a non-illustrated display section, and a substrate conveyance control scheduler 40 for generating a substrate conveyance control schedule. The apparatus computer 30 includes, in addition, hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a memory and a hard disk needed for realizing the operation screen application 31 and the substrate conveyance control scheduler 40.

The apparatus controller 32 is network-connected with the apparatus computer 30, and is configured to receive a substrate conveyance control schedule generated by the substrate conveyance control scheduler 40 from the apparatus computer 30. The apparatus controller 32 is connected with an operation device 50 including the conveyance section and the substrate processing section illustrated in FIG. 1 communicably through an input/output interface. The apparatus controller 32 controls the operation device 50 according to the substrate conveyance control schedule received from the apparatus computer 30.

FIG. 3 is a block diagram of the substrate conveyance control scheduler 40 illustrated in FIG. 2. As illustrated, the substrate conveyance control scheduler 40 includes a modeling section 41, a calculation section 42, a detection section 43, and a connecting section 44. The substrate conveyance control scheduler 40 relating to the present embodiment models processing conditions, processing time and constraints of the plating apparatus 10 into nodes and edges using a graph network theory to be described later, in order to calculate the substrate conveyance schedule. Here, the processing conditions include a kind and order of processing, and a priority degree of the processing, or the like. The processing time includes a start time of each processing, a conveyance start time, time needed for the process, time needed for conveyance, or the like. In addition, the constraints are conditions that constrain the time needed from the start of certain processing to the start of the next processing, or the like. Note that a scheduler is an arithmetic processing unit including at least a storage medium in which software is recorded for receiving signal information from outside and performing a series of arithmetic processing of calculating the substrate conveyance schedule based on the received signal information. Note that the substrate conveyance control scheduler 40 further includes a storage section for storing data information such as the processing time, the constraints and process recipes (processing conditions), and is configured to perform the above-described arithmetic processing while referring to the information preserved in the storage section.

The modeling section 41 models the processing conditions, the processing time and the constraints of the plating apparatus 10 into a graph network expressed by the nodes and the edges using the graph network theory, and calculates a longest route length to each node. The calculation section 42 calculates the substrate conveyance schedule based on the longest route length to each modeled node. The detection section 43 receives a signal from the apparatus controller 32 illustrated in FIG. 2, and detects whether or not the plating apparatus 10 has shifted to a nonstationary state. Here, the nonstationary state includes a state at the time of a fault of the plating apparatus 10, a state at the time of maintenance of the substrate holder, or a state at the time of maintenance of an anode holder or the like, for example.

In addition, in the present embodiment, the connecting section 44 separately calculates the preceding stage side graph network in the apparatus preceding stage section and a subsequent stage side graph network in the apparatus subsequent stage section, connects the preceding stage side graph network and the subsequent stage side graph network, and calculates the graph network relating to the entire plating apparatus 10.

Next, a specific example of calculating the substrate conveyance schedule by the substrate conveyance control scheduler 40 illustrated in FIG. 3 will be described. FIG. 4 is a diagram illustrating one example of the graph network modeled by the modeling section 41 illustrated in FIG. 3. The graph network is simplified for the description.

Premises for modeling the graph network are as follows. That is, two substrate holders holding the substrate to be processed are used. Here, the respective substrate holders are referred to as a first substrate holder (Wafer Holder 1) and a second substrate holder (Wafer Holder 2). The plating apparatus 10 in this example includes four of a unit A, a unit B, a unit C and a unit D, and the processing is started from a state that the two substrate holders are stored in the respectively different unit A. For the units B and C, only one substrate holder can be present. To the respective substrate holders, processing A-D to be the nodes in FIG. 4 is executed. A conceivable order of the processing A-D executed to the respective substrate holders is predetermined based on the process recipe, and the order is indicated by arrows of edges e1-e15 illustrated in FIG. 4. The processing A is takeout processing of the substrate holder from the unit A. The processing B is takeout processing of the substrate holder from the unit B. The processing C is takeout processing of the substrate holder from the unit C. For the processing A, B and C, a series of the processing of takeout of the substrate holder, movement to the next unit and storage in the next unit are continuously executed, respectively. The processing D is storage processing of the substrate holder to the unit D. It is defined that takeout processing time of the processing A-C is 5 seconds, respectively. The processing D is end processing, and the takeout processing time is 0. The respective substrate holders are conveyed one by one by one conveyer. For example, it is defined that moving time of the conveyer between the unit B and the unit C is 3 seconds. It is defined that the moving time of the conveyer between the units B and between the units C is 1 second. To the substrate holder stored in the unit B, the processing of 15 seconds is performed, and to the substrate holder stored in the unit C, processing of 10 seconds is performed. In addition, as the constraints, the time from the start of the processing A to the start of the processing B is 40 seconds or shorter, and the time from the start of the processing B to the start of the processing C is 60 seconds or the like. A list of the premises is illustrated in Table 1 below.

As illustrated in FIG. 4, required time from the processing A to the processing B regarding the first substrate holder is 5 seconds of the takeout processing time from the unit A, 5 seconds of the moving time of the conveyor from the unit A to the unit B, 5 seconds of the storage processing time to the unit B and 15 seconds of the recipe processing time in the unit B, and is 30 seconds as a total. Thus, the edge e1 is 30 seconds. In addition, an edge e4 is 40 seconds as the constraint of the processing between the units A and B. The constraint here is expressed by a negative number. It is similar between the units B and C and between the units C and D. Regarding the first substrate holder, the required time from the processing B to the processing C is 5 seconds of the takeout processing time from the unit B, 3 seconds of the moving time of the conveyor from the unit B to the unit C, 5 seconds of the storage processing time in the unit C and 10 seconds of the recipe processing time in the unit C, and an edge e2 is 23 seconds.

Subsequently, the required time from the processing C to the processing D regarding the first substrate holder is 5 seconds of the takeout processing time from the unit C, 2 seconds of the moving time of the conveyor from the unit C to the unit D and 5 seconds of the storage processing time to the unit D, and is 12 seconds as the total. Thus, an edge e3 is 12 seconds. Regarding the second substrate holder, each of the required time from the processing A to the processing D is similar to that for the first substrate holder.

In the case of shifting from the processing B of the first substrate holder to the processing A of the second substrate holder, in order for the second substrate holder to start the processing A (takeout from the unit A, movement to the unit B and storage), the unit B needs to be free. Therefore, the processing B of the first substrate holder needs to be executed first. That is, 5 seconds of the takeout time from the unit B, 3 seconds of the moving time from the unit B to the unit C, and 5 seconds of the storage processing time to the unit C are needed. In addition, since the processing B is performed last in the unit C and the processing A is performed in the unit A, 7 seconds of the time for the conveyor to move from the unit C to the unit A are needed. Therefore, the required time from the processing B of the first substrate holder to the processing A of the second substrate holder is 20 seconds. Thus, an edge e13 is 20 seconds. An edge e14 is also similarly calculated, and is 16 seconds. Since the recipe processing time of the unit D is 0 second, the edge e15 is 2 seconds of the moving time from the unit D to the unit C.

In a graph network diagram generated by the modeling section 41 illustrated in FIG. 3 as described above, the longest route length to each node is calculated. Here, the modeling section 41 uses a shortest route problem solution approach in order to calculate the longest route length. Specifically, the modeling section 41 inverts positive/negative of a value of the required time of each edge, and a shortest route to each node is calculated by the known shortest route problem solution approach such as Bellman-Ford algorithm. Here, for the shortest route from the processing A of the first substrate holder to the processing C of the first substrate holder for example, the case of successively executing the processing A of the first substrate holder, the processing B of the first substrate holder and the processing C of the first substrate holder is the shortest route (the value is minimum), and the value of the required time is “−53”. The modeling section 41 calculates the value of the shortest route length to each node in this way, and inverts the positive/negative of the value again. The value becomes the value indicating the longest route length to each node. The value indicates the executable fastest processing start time of each processing. Note that the longest route length to each node may be calculated using Dijkstra's algorithm for example, in addition to the Bellman-Ford algorithm.

FIG. 5 is a graph network diagram illustrated in FIG. 4, to which the longest route length to each node is added. Here, 53 seconds of the start time of the processing C of the first substrate holder and 50 seconds of the start time of the processing A of the second substrate holder are confirmed. When the processing A of the second substrate holder of the early start time is started, since the conveyer cannot be used until 5 seconds of the takeout processing, 5 seconds of moving processing from the unit A to the unit B and 5 seconds of storage processing to the unit B elapse, the processing C of the first substrate holder cannot be executed. In addition, unless 3 seconds of the moving time from the last unit B of the processing A to the unit C at a start position of the processing C elapse, the processing C of the first substrate holder cannot be started. In order to avoid contention of the conveyer in this way, an edge e16 for example needs to be added newly as illustrated in FIG. 6. The edge e16 is 18 seconds as described above. FIG. 7 is a graph network diagram updated by calculating the longest route length to each node again after adding the edge e16. Note that a direction of the edge corresponding to the edge e16 may be opposite, and in that case, an edge length is 20 seconds.

In the graph network diagram, in the case that a loop of a positive length is generated by adding the edge, since the execution becomes impossible (the constraint cannot be kept), it is needed to delete the added edge and add a different edge. In an example in FIG. 7, the loop is present among the processing B of the first substrate holder, the processing A of the second substrate holder and the processing C of the first substrate holder, but there is no problem since the total length is 20+18−60=−22.

The longest route length to each node illustrated in FIG. 7 indicates the executable fastest processing start time of each processing. Therefore, when each processing is executed at the time indicated by the value of the longest route length, substrate conveyance processing of high throughput can be performed.

The calculation section 42 prepares a timetable for conveying each substrate holder, that is, the substrate conveyance schedule, based on the value of the longest route length indicated in FIG. 7. FIG. 8 is a diagram illustrating a part of the substrate conveyance schedule. The substrate conveyance control scheduler 40 transmits the substrate conveyance schedule prepared in this way to the apparatus controller 32 illustrated in FIG. 2. The apparatus controller 32 controls the substrate processing section and the conveyance section based on the substrate conveyance schedule.

In this way, according to the substrate conveyance control scheduler 40 relating to the present embodiment, the substrate conveyance schedule is calculated based on the longest route length to each node regarding the nodes and the edges modeled using the graph network theory. Therefore, the substrate conveyance schedule can be calculated without performing advance calculation processing for narrowing down a parameter range so that the calculation amount and the calculation time can be reduced. In addition, since it is not needed to limit parameters (processing conditions) for obtaining the optimum throughput, the substrate conveyance schedule capable of achieving the excellent throughput even in the case that the condition other than the assumed process recipe is given can be calculated.

Next, specific examples of the processing conditions, the processing time and the constraints of the plating apparatus 10 set to the substrate conveyance control scheduler 40 will be described. FIG. 9 is a diagram illustrating one example of conveyance processing time of the loading robot 12 set to the substrate conveyance control scheduler 40. The diagram illustrates the time (seconds) needed for the loading robot 12 to convey the substrate among the one substrate storage container (FOUP 1), the other substrate storage container (FOUP 2), and the spin rinse dryer 14 or the like. For example, the processing time of 1 second is needed for the loading robot 12 to convey the substrate from the FOUP 1 to the FOUP 2. As each required time illustrated in FIG. 9, the value measured beforehand is set to the substrate conveyance control scheduler 40.

FIG. 10 is a diagram illustrating one example of the conveyance processing time of the conveyer 23 set to the substrate conveyance control scheduler 40, and FIG. 11 is a diagram illustrating one example of the conveyance processing time of the conveyer 24 set to the substrate conveyance control scheduler 40. FIG. 10 illustrates the time (seconds) needed for the conveyer 23 to convey the substrate among the fixing stations 15 a and 15 b, the pretreatment bath 18 (Prewet), the washing bath 19 (Presoak) and the blow bath 20 (Blow) or the like. In addition, FIG. 11 illustrates the time (seconds) needed for the conveyer 24 to convey the substrate among the blow bath 20, one plating bath 22, and the other plating bath 22 or the like. Required moving time of each conveyance section illustrated in FIG. 9 to FIG. 11 is set to the substrate conveyance control scheduler 40 beforehand as the processing time.

Subsequently, the constraints set to the substrate conveyance control scheduler 40 will be described. FIG. 12 is a diagram illustrating one example of the constraints set to the substrate conveyance control scheduler 40. As illustrated, in this example, the constraints (seconds) of the pretreatment bath 18 (Prewet), the washing bath 19 (Presoak), the one plating bath 22 (Plating A), and the other plating bath 22 (Plating B) or the like are illustrated. According to the constraints illustrated in FIG. 12, for example, the conveyer 23 has to take out the substrate stored in the pretreatment bath 18 within 30 seconds after pretreatment is ended.

Next, the process recipes and the process processing time set to the substrate conveyance control scheduler 40 will be described. FIG. 13 is a diagram illustrating one example of an entire recipe set to the substrate conveyance control scheduler 40. As illustrated in FIG. 13, the plurality of process recipes are set to the substrate conveyance control scheduler 40. In the illustrated example, recipe IDs “ABC” and “XYZ” are set. In the respective recipe IDs, unit recipes can be selected. In the illustrated example, in the recipe ID “ABC”, the processing in the pretreatment bath 18 (Prewet), the processing in the other plating bath 22 (Plating B), the processing in the blow bath 20 (Blow), and the processing in the spin rinse dryer 14 (SRD) are set to be performed under ordinary conditions (STD: Standard). In addition, in the recipe ID “XYZ”, each illustrated processing is set to be performed under a test condition (TEST).

FIG. 14 is a diagram illustrating one example of the process recipe set to the substrate conveyance control scheduler 40. As illustrated in FIG. 14, the processing time for the ordinary condition (STD) and the test condition (TEST) in the pretreatment bath 18 (Prewet), the washing bath 19 (Presoak), the one plating bath 22 (Plating A), the other plating bath 22 (Plating B), the blow bath 20 (Blow), and the spin rinse dryer 14 (SRD) is set respectively. The ordinary condition and the test condition illustrated in FIG. 13 follow the processing time illustrated in FIG. 14.

Next, a substrate processing method by the plating apparatus 10 relating to the present embodiment will be described. FIG. 15 is a flowchart illustrating the substrate processing method relating to the present embodiment. As illustrated in FIG. 15, first, an operator sets the conveyance processing time of the substrate illustrated in FIG. 9 to FIG. 11 and the constraints illustrated in FIG. 12 to the plating apparatus 10, through a non-illustrated input section provided in the apparatus computer 30 of the plating apparatus 10 (step S101, step S102). The processing time and the constraints in the nonstationary state to be described later are stipulated in the plating apparatus 10 beforehand according to situations of the nonstationary state such as a kind of a fault.

Subsequently, whether or not new lot processing is instructed, that is, new substrate processing is instructed is determined (step S103). When the new lot processing is instructed (step S103, YES), one of the process recipes (processing conditions) illustrated in FIG. 13 is selected, and the processing is started (step S104). Note that the selection of the process recipe may be inputted by the operator through the input section of the apparatus computer 30 or inputted from a non-illustrated host computer network-connected with the apparatus computer 30.

Next, the calculation section 42 of the substrate conveyance control scheduler 40 calculates the substrate conveyance schedule (step S105). A detailed process of step S105 will be described later. When the substrate conveyance schedule, that is, the timetable, is determined by step S105, the apparatus controller 32 executes the substrate processing (step S106).

The detection section 43 detects whether or not the plating apparatus 10 has shifted to the nonstationary state during the execution of the substrate processing (step S107). Here, the nonstationary state includes the state at the time of a fault of the plating apparatus 10, the state at the time of maintenance of the substrate holder, or the state at the time of maintenance of the anode holder or the like. In the plating apparatus 10, a rectifier of the plating bath 22 or the like for example sometimes fails suddenly, and one of the plating baths 22 becomes unusable in this case. In addition, the substrate holder and the anode holder sometimes need cleaning and inspections when used for a long period of time, and are maintained (cleaned or inspected) periodically by being taken out from the plating apparatus 10 or inside the substrate processing apparatus. In this case, the usable substrate holder and the number of the substrate holders are changed, and the throughput of the plating apparatus 10 is affected. Therefore, in the case of determining that the plating apparatus 10 has shifted to the nonstationary state (step S107, YES), the processing returns to step S105, and the substrate conveyance schedule is calculated again based on the processing conditions, the processing time and the constraints in the nonstationary state.

In the case of determining that the plating apparatus 10 has not shifted to the nonstationary state (step S107, NO), whether or not all the substrates within a new lot have been processed is determined (step S108). In the case that the substrate to be processed remains (step S108, NO), the processing returns to step S107, and whether or not the plating apparatus 10 has shifted to the nonstationary state is detected. When all the substrates within the new lot are processed (step S108, YES), the processing of the new lot is ended (S109).

An example of a specific calculation procedure of the substrate conveyance schedule in step S105 illustrated in FIG. 15 will be described. FIG. 16 is a flowchart illustrating subroutines of step S105. As illustrated, in order to calculate the substrate conveyance schedule, first, the data such as the processing time illustrated in FIG. 9 to FIG. 11 and FIG. 14, the constraints illustrated in FIG. 12 and the process recipes (processing conditions) illustrated in FIG. 13 is fetched to the substrate conveyance control scheduler 40 (step S201). Note that, when it is detected that the plating apparatus 10 has shifted to the nonstationary state in step S107 in FIG. 15, in step S201, the data such as the processing conditions, the processing time and the constraints of the plating apparatus 10 in the nonstationary state is fetched to the substrate conveyance control scheduler 40.

Subsequently, the substrate conveyance control scheduler 40 first divides a specified processing number of the substrates into some mini batches of every n substrates (n is an arbitrary number equal to or larger than 1) (step S202). Thereafter, the substrate conveyance control scheduler 40 calculates the graph network of the apparatus preceding stage section (step S203). Thereafter, the substrate conveyance control scheduler 40 calculates the graph network of the apparatus subsequent stage section (step S204).

The connecting section 44 connects the graph network of the apparatus preceding stage section calculated in step S203 and the graph network of the apparatus subsequent stage section calculated in step S204 as the graph network as the entire apparatus, by adding the edge between the related nodes (step S205). Next, when it is confirmed that the calculation is finished for the entire specified processing number, and when the specified processing number is not reached (step S206, NO), the next n substrates are added (step S207), and the processing returns to the processing in step S203. When the specified processing number is reached (step S206, YES), the calculation section 42 calculates the substrate conveyance schedule based on the longest route length to each node in the graph network of the entire apparatus, and transmits the substrate conveyance schedule to the apparatus controller 32 illustrated in FIG. 2, as a substrate conveyance timetable (step S208). The apparatus controller 32 controls the conveyance section of the plating apparatus 10 so as to convey the substrate based on the substrate conveyance timetable.

Subsequently, a specific calculation procedure of the substrate conveyance schedule of the apparatus preceding stage section in step S203 illustrated in FIG. 16 will be described. FIG. 17 is a flowchart illustrating the subroutines of step S203. As illustrated, in order to calculate the substrate conveyance schedule of the apparatus preceding stage section, first, the data such as the processing time, the constraints and the process recipes (processing conditions) related to the apparatus preceding stage section is fetched to the substrate conveyance control scheduler 40 (step S301). From the fetched data, a conveyance order of the apparatus preceding stage section is prepared (step S302). The conveyance order is prepared based on the process recipes (processing conditions) in particular.

Subsequently, the modeling section 41 models the processing conditions, the processing time and the constraints into the nodes and the edges using the graph network theory, and generates the graph network corresponding to each substrate holder as illustrated in FIG. 4 (step S303). When the graph network for the substrate holder of a mini batch processing number given in step S202 illustrated in FIG. 16 is additionally generated (step S304, Yes), the longest route length to each node is calculated based on the generated graph network (step S305).

Next, a specific calculation procedure of the substrate conveyance schedule of the apparatus subsequent stage section in step S204 illustrated in FIG. 18 will be described. FIG. 18 is a flowchart illustrating subroutines of step S204. As illustrated, in order to calculate the substrate conveyance schedule of the apparatus subsequent stage section, first, the substrate conveyance control scheduler 40 acquires the data such as the processing time, the constraints and the process recipes (processing conditions) related to the apparatus subsequent stage section (step S401). From the fetched data, a conveyance order of the apparatus subsequent stage section is prepared (step S402). The conveyance order is prepared based on the process recipes (processing conditions) in particular.

Subsequently, the modeling section 41 models the processing conditions, the processing time and the constraints into the nodes and the edges using the graph network theory, and generates the graph network corresponding to each substrate holder as illustrated in FIG. 4 (step S403). When the graph network for the substrate holder of the mini batch processing number given in step S202 illustrated in FIG. 16 is additionally generated (step S404, Yes), the longest route length to each node is calculated based on the generated graph network (step S405).

As described in FIG. 16, in the present embodiment, the processing conditions, the processing time and the constraints of the apparatus preceding stage section and the apparatus subsequent stage section are modeled respectively, and the preceding stage side substrate conveyance schedule in the apparatus preceding stage section and the subsequent stage side substrate conveyance schedule in the apparatus subsequent stage section are separately calculated. Therefore, the calculation is simplified compared to the case of calculating the substrate conveyance schedule of the entire apparatus, and the calculation amount and the calculation time can be reduced. Note that the apparatus preceding stage section and the apparatus subsequent stage section may be put together and the substrate conveyance schedule may be calculated at once.

Another example of a specific calculation procedure of the substrate conveyance schedule in step S105 illustrated in FIG. 15 will be described. FIG. 19 is a flowchart illustrating subroutines of step S105. In the flow illustrated in FIG. 19, graph networks are prepared defining a predetermined number of the substrates as one unit (mini batch) and fixes a graph network for one of those substrates. Subsequently, graph networks for the substrates in the next one unit are prepared additionally to the already fixed graph network, and fixes a graph network for further one substrate. Therefore, the graph networks for the two substrates are fixed. This is successively repeated to prepare graph networks for a specified processing number. Hereinafter, detailed processing will be described with reference to FIG. 19.

As illustrated, in order to calculate the substrate conveyance schedule, first, the data such as the processing time illustrated in FIG. 9 to FIG. 11 and FIG. 14, the constraints illustrated in FIG. 12 and the process recipes (processing conditions) illustrated in FIG. 13 is fetched to the substrate conveyance control scheduler 40 (step S501). Note that, when it is detected that the plating apparatus 10 has shifted to the nonstationary state in step S107 in FIG. 15, in step S501, the data such as the processing conditions, the processing time, and the constraints of the plating apparatus 10 in the nonstationary state is fetched to the substrate conveyance control scheduler 40.

Subsequently, the substrate conveyance control scheduler 40 defines, as n, the number of substrates in the mini batch to be processed out of the entire number (referred to as specified processing number) of the substrates for which graph networks are to be prepared (step S502). In other words, the predetermined number n of the substrates out of the specified processing number is defined as one unit. In the illustrated example, 3 is set as the set value n. Note that n can be defined as an arbitrary integer equal to or larger than 1. Thereafter, the substrate conveyance control scheduler 40 defines an additional substrate number as m and sets an initial value as 1 (step S503). Here, the additional substrate number is a variable for indicating a substrate for which a graph network is to be prepared. Next, a start time fixing determination number is defined as k, and for example, 10 is set as a set value (step S504). Note that k can be defined as an arbitrary integer not smaller than 1.

The substrate conveyance control scheduler 40 sets nc[m] for each substrate m as a “successive count without a change in start time” (step S505). For example, nc[1] is set to the substrate of m=1, and nc[2] is set to the substrate of m=2. In the illustrated example, 0 is set as an initial value of nc[m]. The modeling section 41 of the substrate conveyance control scheduler 40 prepares graph networks for mth to (m+n−1)th substrates, and performs optimization using a local search method for modification based on a critical path, for example (step S506). That is, when m is 1 and n is 3, the substrate conveyance control scheduler 40 prepares graph networks for the first to third substrates and optimizes these graph networks. In step S506, in addition to the above, the modeling section 41 calculates a start time of each processing of each substrate as illustrated in FIG. 8.

Next, the substrate conveyance control scheduler 40 confirms whether or not (m+n−1) has become equal to or larger than the specified processing number (step S507). That is, the substrate conveyance control scheduler 40 confirms whether preparation of graph networks has been ended for all the specified processing number. When (m+n−1) reaches the specified processing number (step S507, YES), the calculation section 42 calculates the substrate conveyance schedule based on the longest route length to each node in the graph network for the entire apparatus, and transmits the substrate conveyance schedule to the apparatus controller 32 illustrated in FIG. 2, as a substrate conveyance timetable (step S512). The apparatus controller 32 controls the conveyance section of the plating apparatus 10 so as to convey the substrate based on the substrate conveyance timetable.

When (m+n−1) has not reached the specified processing number (step S507, NO), the graph networks for the first to mth substrates are left, and the graph networks for the (m+1)th to (m+n−1)th substrates are deleted (step S508). For example, when m is 1 and n is 3, the graph network for the first substrate is left and the graph networks for the second to third substrates are deleted. Next, the graph networks for the first to mth substrates are fixed (step S509). That is, when m is 1, only the graph network for the first substrate is fixed. Here, fixing of the graph network means, for example, making unchangeable the nodes, edges connected to the nodes, and the lengths of edges as illustrated in FIGS. 4 to 7.

Subsequently, the substrate conveyance control scheduler 40 performs processing of fixing the start time of the processing on the substrate, the start time having been calculated in step S506 (S510). The processing start time fixing processing will be described later. After completion of the processing start time fixing processing, in order to perform calculation of the next substrate, 1 is added to m (step S511), and the processing returns to step S506.

In step S506, graph networks for mth to (m+n−1)th substrates, m having been added with 1, are additionally prepared and optimized, and start times of the graph networks are calculated. For example, when m is 2 and n is 3, the graph networks for the second to fourth substrates are prepared additionally to the first substrate, optimized, and start times thereof are calculated. That is, in step S506 from the second time on, out of the remaining substrates except for the substrate for which the graph network has already been fixed, n substrates are defined as the other one unit, graph networks for each of the substrates in this one unit are prepared and added to the already fixed graph networks. In this way, in step S506 from the second time on, the graph networks for the mth to (m+n−1)th substrates are added to the already fixed graph networks for the first to (m−1)th substrates. At this time, by adding the graph networks for the mth to (m+n−1)th substrates to the graph networks for the first to (m−1)th substrates, critical paths in the graph networks for the first to (m−1)th substrates can change. In this case, a start time of each of the processing in the graph networks for the first to (m−1)th substrates can also change.

Subsequently, when (m+n−1) does not reach the specified processing number (S507, No), the processing from step S508 to step S511 is repeated. In Step S508 and step S509, when m is 2 and n is 3, the graph networks for the first to second substrates are fixed, and the graph networks for the third to fourth substrates are deleted. In other words, in addition to the already fixed graph network for one substrate, one of three substrates the graph networks for which have been added is fixed to the already fixed graph network for one substrate. Therefore, by repeating from step S508 to step S511, a graph network for one substrate is successively added to the already fixed graph networks.

As illustrated in FIG. 19, in this example, while a predetermined number of the substrates is defined as one unit (mini batch) and graph networks for the substrates are prepared and optimized, the graph network is fixed for each substrate. Therefore, it is possible to more easily obtain an efficient conveyance order and to reduce the calculation time. In addition, since a graph network can be additionally prepared for each substrate, even when a new substrate is fed during execution of the substrate conveyance, it is possible to deal with such supply.

FIG. 20 is a flowchart illustrating subroutines of step S510 illustrated in FIG. 19. In the flow illustrated in FIG. 20, in step S506 in FIG. 19, on each of the first to (m+n−1)th substrates for which the graph networks have been prepared and the start time of each processing has been calculated, the processing of fixing the start time of each processing is performed. Hereinafter, a detail will be described.

As illustrated in FIG. 20, the substrate conveyance control scheduler 40 defines an internal arithmetic substrate number as p, and sets 1 to this number as an initial value (step S601). Note that the internal arithmetic substrate number is a variable for indicating a substrate to which the processing start time fixing processing is to be performed. Subsequently, the substrate conveyance control scheduler 40 determines whether or not start times of all the processing relating to a substrate p have changed (step S602). Specifically, when step S506 in FIG. 19 is repeated a plurality of times, the substrate conveyance control scheduler 40 determines whether or not the start time of each processing calculated in the last step S506 has changed from the start time of each processing calculated in step S506 immediately prior thereto. In other words, when the graph network prepared in step S506 is added to the graph network fixed in step S509 in FIG. 19, it is determined whether or not the start time of the processing on the substrate, for which the graph network has already been fixed, has changed.

When it is determined that the start time of each processing has changed in step S602 (step S602, No), the substrate conveyance control scheduler 40 sets nc[p] to 0 (step S603), and the processing continues to step S607. Note that when step S506 has been performed just once in the past in the determination of step S602, it is considered that the start time of each processing has changed (step S602, No), and nc[p] is set to 0 (step S603).

On the other hand, when it is determined that start time of each processing has not changed in step S602 (step S602, Yes), the substrate conveyance control scheduler 40 adds 1 to nc[p] (step S604). Subsequently, the substrate conveyance control scheduler 40 compares nc[p] with the start time fixing determination number k and determines whether or not nc[p] is equal to or larger than k (step S605). That is, the processing of step S605 can also be said to be processing of confirming the reliability of the start time of each processing relating to a substrate p, calculated by the processing of step S506 in FIG. 19. When nc[p] has not reached k (step S605, No), the processing goes to step S607. When nc[p] has reached k (step S605, Yes), the start time of each processing on the substrate p is fixed (step S606).

Subsequently, the substrate conveyance control scheduler 40 determines whether or not the value p is equal to or larger than (m+n−1) (step s607). That is, in the processing of step S607, it is determined whether or not the processing from step S602 to step S606 has been performed on all the substrates for which the graph networks have been prepared from step S506 to step S509 in FIG. 19. When the value p is determined to be smaller than (m+n−1) (step S607, No), 1 is added to p (step S608), and the processing from step S602 to step S606 is repeated.

On the other hand, when the value p is determined to be equal to or larger than (m+n−1) (step S607, Yes), the start time of each processing on each of the substrates 1 to (m+n−1) is preserved in the non-illustrated storage section (step S609).

As illustrated in FIG. 20, when the start time of each processing on the substrate p remains unchanged over a predetermined period, the start time of each processing is fixed. This enables reduction in calculation processing of the longest route length.

In addition, according to the present embodiment, as illustrated in FIG. 15, even when the plating apparatus 10 shifts to the nonstationary state, since the substrate conveyance schedule is calculated based on the processing conditions, the processing time and the constraints, the substrate conveyance schedule appropriate in the nonstationary state can be calculated. Specifically, the appropriate substrate conveyance schedule in a sudden nonstationary state such as the fault of the plating apparatus 10 can be calculated. In addition, even in the nonstationary state that periodically occurs such as the maintenance of the substrate holder and the anode holder, the appropriate substrate conveyance schedule can be calculated.

While the embodiment of the present invention is described above, the embodiment of the invention described above is intended to facilitate understanding of the present invention, and does not limit the present invention. It is apparent that the present invention may be modified or improved without departing from the scope thereof, and the present invention includes equivalents thereof. Also, in the scope that at least part of the above-described problem can be solved or the scope that at least part of effects is presented, each component described in the scope of claims and the description can be arbitrarily combined, or omitted.

REFERENCE SIGNS LIST

10 . . . Plating apparatus

11 . . . Loading port

12 . . . Loading robot

14 . . . Spin rinse dryer

15 a, 15 b . . . Fixing station

23 . . . Conveyer

24 . . . Conveyer

26 . . . Plating area

30 . . . Apparatus computer

31 . . . Operation screen application

32 . . . Apparatus controller

40 . . . Substrate conveyance control scheduler

41 . . . Modeling section

42 . . . Calculation section

43 . . . Detection section

44 . . . Connecting section 

What is claimed is:
 1. A scheduler incorporated in a control section of a substrate processing apparatus including a plurality of substrate processing sections that process a substrate, a conveyance section that conveys the substrate, and the control section that controls the conveyance section and the substrate processing sections, and calculating a substrate conveyance schedule, the scheduler comprising: a modeling section that models processing conditions, processing time and constraints of the substrate processing apparatus into nodes and edges by using a graph network theory, prepares a graph network, and calculates a longest route length to each node; and a calculation section that calculates the substrate conveyance schedule based on the longest route length, wherein the modeling section defines as one unit a predetermined number of the substrates out of the substrates for which graph networks are to be prepared and prepares a graph network for each of the substrates, wherein the scheduler fixes one of the prepared graph networks, wherein the modeling section defines as another one unit a predetermined number of the substrates out of the substrates for which graph networks are to be prepared except for the substrates for which the graph networks have already been fixed, and prepares a graph network for each of the substrates in the other one unit to add to the fixed graph network, and wherein the scheduler fixes one of the added graph networks.
 2. The scheduler according to claim 1, wherein a start time of the processing on the substrate for which the graph network has been prepared is calculated, and wherein the start time of the processing is fixed.
 3. The scheduler according to claim 2, wherein the start time of the processing on the substrates for which the graph network has been fixed is fixed when the start time of the processing remains unchanged at the time of adding the graph network for the substrate in the other one unit to the fixed graph network.
 4. The scheduler according to claim 1, wherein the modeling section prepares graph networks for all the substrates for which graph networks are to be prepared.
 5. The scheduler according to claim 1, comprising a detection section that detects whether or not the substrate processing apparatus has shifted to a nonstationary state, wherein the modeling section models the processing conditions, the processing time and the constraints of the substrate processing apparatus in the nonstationary state to the nodes and the edges using the graph network theory when the detection section detects that the substrate processing apparatus has shifted to the nonstationary state, prepares the graph network, and calculates the longest route length to each node, and wherein the calculation section is configured to calculate the substrate conveyance schedule based on the longest route length to each node in the nonstationary state.
 6. The scheduler according to claim 5, wherein the nonstationary state includes a state at the time of a fault of the substrate processing apparatus, a state at the time of maintenance of the substrate holder, or a state at the time of maintenance of an anode holder.
 7. A substrate processing apparatus comprising the control section incorporating the scheduler according to claim 1, wherein the control section is configured to control the conveyance section based on the calculated substrate conveyance schedule.
 8. A substrate conveyance method using a substrate processing apparatus including a plurality of substrate processing sections that process a substrate, a conveyance section that conveys the substrate, and a control section that controls the conveyance section and the substrate processing sections, the method comprising: a modeling step of modeling processing conditions, processing time and constraints of the substrate processing apparatus into nodes and edges by using a graph network theory, preparing a graph network, and calculating a longest route length to each node; a calculation step of calculating a substrate conveyance schedule based on the longest route length; and a step of conveying the substrate based on the substrate conveyance schedule, wherein the calculation step includes a step of defining as one unit a predetermined number of the substrates out of the substrates for which graph networks are to be prepared and preparing a graph network for each of the substrates, a step of fixing one of the prepared graph networks, a step of defining as another one unit a predetermined number of the substrates out of the substrates for which graph networks are to be prepared except for the substrates for which the graph networks have already been fixed, and preparing a graph network for each of the substrates in the other one unit to add to the fixed graph network, and a step of fixing one of the added graph networks.
 9. The substrate conveyance method according to claim 8, wherein the calculation step includes a step of calculating a start time of the processing on the substrate for which the graph network has been prepared, and a step of fixing the start time of the processing.
 10. The substrate conveyance method according to claim 9, wherein the step of fixing the start time of processing fixes the start time of the processing on the substrates for which the graph network has been fixed when the start time of the processing remains unchanged at the time of adding the graph network for the substrate in the other one unit to the fixed graph network.
 11. The substrate conveyance method according to claim 8, comprising a step of detecting whether or not the substrate processing apparatus has shifted to a nonstationary state, wherein the modeling step includes a step of modeling the processing conditions, the processing time and the constraints of the substrate processing apparatus in the nonstationary state to the nodes and the edges using the graph network theory when it is detected that the substrate processing apparatus has shifted to the nonstationary state, preparing the graph network, and calculating the longest route length to each node, and wherein the calculation step includes a step of calculating the substrate conveyance schedule based on the longest route length to each node in the nonstationary state.
 12. The substrate conveyance method according to claim 11, wherein the nonstationary state includes a state at the time of a fault of the substrate processing apparatus, a state at the time of maintenance of the substrate holder, or a state at the time of maintenance of an anode holder. 